On modern aircraft, the instrument panel includes electronic displays for presenting to the pilot the important flight or navigation control information.
The information useful for navigation is:                cartographic data concerning the terrain being flown over, taken from digital databases;        information linked to the aeronautical maps such as the obstacles, beacons, air routes, aeronautical zones, terminal management approaches (TMA) and control zones (CTR).        
An aeronautical zone is a zone defined by the aeronautical regulations. The main zone types are TMA, CTR and restricted or prohibited access zones. These zones are delimited by a geographic contour, by a ceiling altitude and a floor altitude. These zones also have associated names and radio frequencies.
The aeronautical zones are normally represented by a series of geometrical figures, particularly on paper aeronautical maps. They are conventionally represented by a fine continuous line, defining the limit of the zone and by a semi-transparent border indicating the interior side of the zone. The line and the border are colored according to the type of aeronautical zone, the color being defined by air regulations. For example, prohibited access zones are red, restricted access zones are magenta.
A box is associated with each zone containing a key, the content of which is regulated. The box contains the name of the zone and, where appropriate, its radio frequency, its type, its ceiling and its floor.
Digital cartography presentations on electronic displays rarely include the information associated with the aeronautical maps which contain an excessive density of information. FIG. 1 represents a cartographic image 1 in plan view of a terrain being flown over by an aircraft, the cartographic image containing both relief information 3 described by horizontally cross-hatched lines and information 2 linked to the aeronautical maps. The boundaries of the aeronautical zones are described by oblique cross-hatched lines bounded by a fine continuous line. The aeronautical zones 2 overlap, making the map difficult to read. All the boxes 4 are displayed, which further clutters the display without actually providing the pilot with important information. Consequently, the presentation becomes illegible to the user.
However, an aircraft moving in an air space needs to be able to anticipate entry into an aeronautical zone. Depending on circumstances, the pilot needs to avoid the zone, contact a radio frequency before entering it or take special measures concerning air regulations. It is therefore important for a pilot to know the geographic position of these zones and anticipate entry into these zones.